Asphalt cores are removed from a road surface for subsequent testing in order to determine the structural characteristics of the road surface. One such characteristic is the density of the road surface. This is particularly important because of the granular and aggregate makeup of paving materials, which can have voids and other gaps that impact the structural integrity of the road surface.
Due to the interconnected voids and gaps found in an asphalt core, and the moisture content trapped within the voids due to the environment or core extraction process, it is important to remove the moisture from the asphalt core in order to determine a dry density or other mechanistic or volumetric parameter thereof. Removing the moisture content can be time consuming. One could air dry the core, but doing so would take an unacceptably long time. One could apply heat to the core, but doing so could cause unintended consequences to the core integrity. Previous attempts to dry cores involved lowering the pressure surrounding the core. This results in rapidly lowering the sample temperature through an evaporation process. Relying exclusively on heat conduction from a support or plate, or typical convection methods is not a reasonable solution; as with a vacuum process, convection does not exist. Infrared Radiation heats only the surface of the sample or core, thus further relying on the conduction of heat energy from the surface to gradually heat the center or volume of the sample. By incorporating RF, RF induction, or microwave sources, a substantial volume of the core or pavement material is instantly filled with energy, thermally inducing evaporation and drastically reducing time to remove the moisture.
A need therefore exists for a method or solution that addresses these disadvantages.